Microinjection of purified DNA constructs for the production of transgenic mice. This includes injection of a single transgene construct (plasmid-based or BACs) that has been prepared by the investigator. A minimum of 2 transgenics or 20 live births (or embryos), whichever comes first, is prepared for each set of injections charged to an investigator. Standard transgenic founders are established in either B6D2 hybrids or FVB/N inbreds, while injections can be done in less efficient strains (such as C57Bl/6J) as well. (The cost of mice and health testing are an additional cost and will be added at the time of billing.)

Protocols for the purification of plasmid-based transgenes that are less than 20 kb, and for the purification of tail DNAs for genotyping of potential founders as follows:

Genome Editing (hybrid strains-$2,700; inbred strains $3,380)

Recent advances in the field have allowed the MGGT CoRE to use CRISPR technology to do genome editing in vivo. This approach allows the CoRE to create novel targeted genes (knock-outs, knock-ins, etc.) in as little as 1-2 months, compared with the generation of similar targeted models using ES cells which can take 6-12 months, or more. (The cost of mice and health testing are an additional cost and will be added at the time of billing.)

IVF rederivation ($1,350)

Mouse lines can be imported into Mount Sinai by obtaining 1-2 males from a collaborator at another institution. These males are used to prepare sperm for in vitro fertilization (IVF) of wild-type mouse oocytes. The fertilized embryos are transferred to specific pathogen-free hosts to generate clean mice.

(The cost of mice and health testing are an additional cost and will be added at the time of billing.)

IVF and frozen embryo recovery ($1,350)

The MGGT CoRE recovers lines from which sperm have been frozen and stored at Mount Sinai. Cryopreserved sperm samples are maintained in two separate locations to minimize losses in the case of a freezer failure. The MGGT CoRE also works with investigators to import lines of mice into Mount Sinai through the use of live, early-stage embryos, frozen embryos or frozen sperm. These methods can offer a relatively quick solution to importation of animals that avoids quarantine issues such quarantine space, and the quarantine time itself. (The cost of mice and health testing are an additional cost and will be added at the time of billing.)

Microinjection of selected embryonic stem (ES) cell clones into mouse blastocysts to establish chimeric mice for the production of "knockout" mouse lines. Depending upon the goals of the study, live offspring, or pre-implantation or mid-gestation embryos can be provided. (The cost of mice and health testing are an additional cost and will be added at the time of billing.)

ES Cell Karyotyping ($174/clone)

The quality of ES cells can be assessed prior to injection to create chimeric mice by karyotyping individual ES clones. This should be considered whenever possible, especially in cases where multiple clones are available, so that the best clones can be chosen for microinjection into blastocysts.

The long-term storage of mouse sperm and/or embryos reduces the need for constant maintenance of lines which are not essential for current research needs, as well as providing a backup repository of important lines in case of environmental or weather-related crises. (The cost of mice for the CryoPlus service is an additional cost and will be added at the time of billing.)

Embryo rederivation ($1,140)

Mouse lines infected with various mouse pathogens can be cleaned up by transfer of embryos to pathogen-free hosts. This will allow these lines to be shipped to collaborators at other institutions or to be moved into cleaner, barrier facilities at Mount Sinai. (The cost of mice and health testing are an additional cost and will be added at the time of billing.)

Shipment of Cryopreserved Sperm ($150)

Cryopreserved sperm samples can be shipped from Mount Sinai to collaborators around the world. This service includes preparation and loading of dry liquid nitrogen shippers with frozen sperm samples.

Mouse Embryos ($500)

The MGGT CoRE can provide mouse embryos at various preimplantation stages. (The cost of mice is an additional cost and will be added at the time of billing.)

ES cell generation from existing lines ($2,600)

The MGGT CoRE can produce ES cells from blastocysts of existing mouse lines. This is a useful technique for laboratories that would like to generate their own ES cells for in vitro or in vivo studies.

ES Cell Subcloning ($2,700)

The CoRE can use sub-cloning techniques to produce high quality ES cells from lines which have lost their germline potential. This approach will be useful in cases where ES cells fail to produce germline transmission due to changes in karyotype, etc.

Services and Timeline FAQs

Below we answer some of the most frequently asked questions about our services.

A: New projects need to be added to the schedule of existing projects. A few weeks will usually be needed from the time a request is received for mice to be ordered for a project and delivered into the facility's animal housing room. In most cases, the facility can usually begin a project within 2-3 weeks of receiving a request and injection materials, but this is dependent on the existing schedule.

A: It usually takes several months from the time a request is received until founders are available for an investigator's use. Assuming a minimum of 2 weeks for ordering and receiving the mice needed for a project, 3 weeks for gestation, 3 weeks for lactation, and 2 weeks for health testing post-weaning, it is usually a minimum of 10 weeks from request receipt to transfer of founders to a PI. This can be lengthened by factors such as the need for repeat injections, problems with the quality of injection material, etc.

A: No, the facility does not breed founders. There is insufficient space and resources for the facility to do this. If an investigator needs assistance with breeding of founders, they should contact the Rodent Colony Management Program.

A: It depends. Cryopreserving embryos is more complicated because it usually requires female mice of a certain age (5-6 weeks old) to be superovulated and mated with males of the same line that are 3-10 months of age. For each attempt at embryo cryopreservation, at least 10-12 females (and an equal number of males for the mating) are required, and this is usually difficult to organize with the requesting lab.

A: The CoRE facility has successfully used males greater than 24 months of age to rescue mouse lines by IVF. This is not ideal, however, since as males age they tend to have reduced or no sperm counts, which make IVF recovery less likely with age.